Who is listening on a given TCP port on Mac OS X?

Question

On Linux, I can use netstat -pntl | grep $PORT or fuser -n tcp $PORT to find out which process (PID) is listening on the specified TCP port. How do I get the same information on Mac OS X?

Answer 1

Update January 2016

Really surprised no-one has suggested:

lsof -i :PORT_NUMBER

to get the basic information required. For instance, checking on port 1337:

lsof -i :1337

Other variations, depending on circumstances:

sudo lsof -i :1337
lsof -i tcp:1337

You can easily build on this to extract the PID itself. For example:

lsof -t -i :1337

which is also equivalent (in result) to this command:

lsof -i :1337 | awk '{ print $2; }' | head -n 2 | grep -v PID

Quick illustration:

For completeness, because frequently used together:

To kill the PID:

kill -9 <PID>
# kill -9 60401

or as a one liner:

kill -9 $(lsof -t -i :1337)

Answer 2

On macOS, here's an easy way to get the process ID that's listening on a specific port with netstat. This example looks for a process serving content on port 80:

find server running on port 80

netstat -anv | egrep -w [.]80.*LISTEN

sample output

tcp4  0 0  *.80       *.*    LISTEN      131072 131072    715      0

The 2nd from the last column is the PID. In above, it's 715.

options

-a - show all ports, including those used by servers

-n - show numbers, don't look up names. This makes the command a lot faster

-v - verbose output, to get the process IDs

-w - search words. Otherwise the command will return info for ports 8000 and 8001, not just "80"

LISTEN - give info only for ports in LISTEN mode, i.e. servers

Answer 3

on OS X you can use the -v option for netstat to give the associated pid.

type:

netstat -anv | grep [.]PORT

the output will look like this:

tcp46      0      0  *.8080                 *.*                    LISTEN      131072 131072   3105      0

The PID is the number before the last column, 3105 for this case

Answer 4

lsof -n -i | awk '{ print $1,$9; }' | sort -u

This displays who's doing what. Remove -n to see hostnames (a bit slower).

Answer 5

This did what I needed.

ps -eaf | grep `lsof -t -i:$PORT`

Answer 6

On macOS High Sierra, use this command:

lsof -nP -i4TCP:$PORT | grep LISTEN

On older versions, use one of the following forms:

lsof -nP -iTCP:$PORT | grep LISTEN
lsof -nP -i:$PORT | grep LISTEN

Substitute $PORT with the port number or a comma-separated list of port numbers.

Prepend sudo (followed by a space) if you need information on ports below #1024.

The -n flag is for displaying IP addresses instead of host names. This makes the command execute much faster, because DNS lookups to get the host names can be slow (several seconds or a minute for many hosts).

The -P flag is for displaying raw port numbers instead of resolved names like http, ftp or more esoteric service names like dpserve, socalia.

See the comments for more options.